Re: [CAD_CAM_EDM_DRO] Re: Controlling more stepper drivers than I have outputs for?

At 12:37 PM 4/16/02 -0000, you wrote:

>Do you have an "automatic" switchover between regular spindle motor
>and the "C" axis stepper drive? A long time ago I saw this on a
>commercially offered lathe, but didn't pay enough attention :-(

I have the spindle stepper drive mounted to HS face on two screws, so the
entire rig is ez on/off. It drives a layshaft by cog-belt, same parts used
as for the lead screws. The layshaft also has a pinion, and mounted on
chuck backplate (and on a faceplate also) is the final gear. <=Hence these
come on and off spindle with the chuck or faceplate. I did this to get
enough reduction, about 4600 steps/rev, which figure can be put into config
by user and saved with the rest of user's defaults and re-loaded with the
config file. The layshaft is on a pivot, so I can swing it in/out of
engagement manually. The software uses 'c' axis for threading, and I must
hence also swap a cable over from the vert axis. I can change the code to
let user pick an axis with which to drive the spindle; after all I-LPT
gives you either six or eight to choose from. But unless one rigs a device
to engage and disengage the gears one would still have to do those shifts
by hand. Doing it under power would also require one to use an extra axis
for outputting the bit that did the shifting, and one would need a shift
mechanism, possibly something like a small motorcycle trans with most of
the works trashed and a solenoid to shift in/out of last remaining gear
pair. (That's really only appropriate since I'm using MC gears now to make
the final coupling-up to spindle.) This rig so far has been reliable and
produces very good results and it takes only a few seconds to shift over to
threading or back to turning.

Regards, Hoyt

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